518 



Report of the State Geologist. 



ner border of the polyzoary ; not straight, but forming a spiral, 

 rounded, nonporiferous or slightly poriferous inner margin." 









Fig. 70. ▲ photo-engraving of Claypole's original illustration. Fig. 1, Helicopora lati^piralis. 

 Lower face, showing four whorls of the spiral, nat. size; 2, H. Ulrichi, x8; 2a, A small portion, x8; 

 3, H. arehimediformia, nat. size ; 4, Enlarged view of the cellulif erous part of fig. 8, x4. 



